White cloud mountain minnow

Quick facts

Adult size

4 cm

Lifespan

can live up to 7 years; long-lived for a small fish; 5-7 years routine

Tank zone

all

Temperament

peaceful

Difficulty

beginner

Schooling

recommended 6+ (critical minimum 5, thrives at 10+)

Water parameters

Temperature

14–22°C

pH

6.0 to 8.0

Hardness

5 to 20 dGH

Tank requirements

Minimum volume

38 L

Minimum length

45 cm

Flow

low

Lighting

dim preferred

Substrate

any

Open swimming room

needed

Feeding

Diet: omnivore, feeds primarily at the all.

Omnivore that eats anything small enough for its mouth. Flake food, micro pellets, frozen daphnia, frozen brine shrimp, frozen cyclops, and live food. Feeds at the surface and mid-water. Small mouths; crush large flakes. Feed twice daily. Not picky. In outdoor tubs and ponds during summer, they eat mosquito larvae and other aquatic insects without supplemental feeding.

Compatibility

• Cold-water fish that's often overlooked because tropical tanks dominate the hobby. White clouds thrive at 18–22°C, which means they do best in unheated tanks or subtropical setups, not in standard tropical communities at 25–26°C.
• Peaceful and schooling. Groups of 8+ produce the best display, with males competing and showing off their red fin coloring. In smaller groups they fade and hide.
• Good companions: peppered corys, weather loaches, paradise fish, hillstream loaches, and variatus platies. Anything that prefers the same cool temperature range.
• Sometimes sold as feeder fish, which is a disservice. A big school of white clouds in a planted tank at room temperature is as attractive as any tropical community.

Habitat

Native to streams around White Cloud Mountain (Baiyun Shan) near Guangzhou in Guangdong Province, China. The original population was believed to be extinct in the wild for decades, but small populations were rediscovered in the 2000s. The wild habitat is cool, clear, fast-flowing mountain streams at elevation. Temperature in these streams rarely exceeds 22°C, which is why white clouds prefer cooler water than most tropical fish. The species was first collected in 1932 by a Chinese boy scout named Tan Kam Fei, and the discoverer's name became part of the scientific name: Tanichthys albonubes. In the aquarium hobby since the 1930s, it was once marketed as "the poor man's neon tetra" because it was colorful but didn't need a heater. Adults are small (3–4 cm) with a dark lateral stripe bordered by iridescent blue-green, red-tipped fins, and a metallic sheen on the body. A long-finned variant and a golden variant have been bred. All hobby stock is captive-bred; wild collection is prohibited and the species is listed as Vulnerable by the IUCN.

Breeding

One of the easiest egg-layers to breed. In an established planted tank at room temperature, they'll breed continuously with no intervention. Eggs are scattered among fine-leaved plants and moss. Adults don't eat the eggs as aggressively as most tetras, which means fry survival in planted tanks is reasonable even without a separate breeding setup. Eggs hatch in 48-72 hours at 20°C. Fry are tiny but can eat baby brine shrimp within a few days. A dedicated breeding tank with a spawning mop or dense Java moss maximizes yield. Temperature at 20–22°C. No special water chemistry required. The species is so easy to breed that outdoor ponds and tubs in temperate climates produce fry all summer with zero management. This ease of breeding is why white clouds cost almost nothing in stores.

Common problems

Being kept too warm is the primary issue. White clouds sold in tropical sections of fish stores get stocked into 26°C community tanks where they survive but don't thrive. They become lethargic, their coloring fades, their lifespan shortens (from 5+ years at cool temperatures to 2-3 years at tropical temperatures), and they're more susceptible to disease. Room temperature (18–22°C) is ideal. Ich can occur when fish are thermally stressed. The velvet disease (Piscinoodinium) occasionally hits white clouds, showing as a fine gold or rust-colored dusting on the body. Treat with darkness (cover the tank for 3-4 days, as the parasite is light-dependent) plus an anti-parasitic medication. Otherwise, white clouds are extremely hardy, disease-resistant, and trouble-free when kept at appropriate temperatures.

Outdoor pond suitability

This species is suited to outdoor ponds, not just indoor aquariums.

Climate classification

temperate

Outdoor pond zones (USDA)

4 to 10 (winter low around -34°C or warmer)

Outside the zone range, this species can still be kept indoors. Within the zone, an outdoor pond at least 60 cm deep usually has enough thermal mass to overwinter the species, though local frost depth and surface freezing matter.

Bioload

Bioload coefficient: 0.7 (similar size to glowlight tetra but cold-water metabolism).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size